/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.apache.streampipes.processors.filters.jvm.processor.movingaverage.util;

import java.util.ArrayList;
import java.util.List;

public abstract class MovingFilter {
  private int n;
  private double filteredMeasurement;
  private List<Double> measurements;

  public MovingFilter(int n) {
    this.n = n;
    measurements = new ArrayList<Double>();
  }

  public double update(double newMeasurement) {
    measurements.add(newMeasurement);
    if (measurements.size() > n) {
      measurements.remove(0);
    }
    filteredMeasurement = filterMeasurement(measurements);
    return filteredMeasurement;
  }

  public double getFilteredMeasurement() {
    return filteredMeasurement;
  }

  protected abstract double filterMeasurement(List<Double> measurements);
}
